time.c (time_timespec): fix tv_nsec overflow

test/ruby/test_float.rb (test_sleep_with_Float) causes tv_nsec
to hit 1000000000 exactly.  This bug is currently hidden from
our test by the platform-dependent native_cond_timeout
functions, but a future native_cond_timedwait implementation may
prefer relative timeouts to match ConditionVariable#wait
semantics more closely.
[Bug #10144]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47196 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 4 insertions, 0 deletions

diff --git a/time.c b/time.c
index 04f99f2dca..7ba83bbea7 100644
--- a/time.c
+++ b/time.c
@@ -2354,6 +2354,10 @@ time_timespec(VALUE num, int interval)
 	    d = modf(RFLOAT_VALUE(num), &f);
 	    if (d >= 0) {
 		t.tv_nsec = (int)(d*1e9+0.5);
+		if (t.tv_nsec >= 1000000000) {
+		    t.tv_nsec -= 1000000000;
+		    f += 1;
+		}
 	    }
 	    else if ((t.tv_nsec = (int)(-d*1e9+0.5)) > 0) {
 		t.tv_nsec = 1000000000 - t.tv_nsec;